By the time the compact equipment industry reaches full Tier 4 (T4) compliance in 2015, every machine with 25.5 horsepower (hp) or more will feature added special emission technologies. While every manufacturer will offer a Tier 4 compliant solution for their machines, Bobcat will offer a unique solution, including a new product line of Bobcat® Engines that provide Tier 4 compliance plus several other benefits.
Bobcat Engines have a specially designed combustion chamber that minimizes the amount of Particulate Matter (PM) the engine creates. The amounts are low enough that a Diesel Particulate Filter (DPF) isn’t needed for Tier 4 compliance. This “non-DPF” solution induces simplicity because most DPFs require interaction and maintenance from the operator to keep the engine operating properly.
Chart 1 outlines the Bobcat machines that will eventually receive a Bobcat Engine. The implementation timeframe spans from November 2013 – 2015*. Chart 1 also lists emission technologies, besides the Bobcat Engine, that will be used in Bobcat machines for Tier 4 compliance. Each solution is managed by the machine's electronic control unit (ECU), meaning operators likely won’t even notice these technologies. The operator experience is minimally affected, which is another benefit of this Tier 4-compliant solution.
Engine combustion pressure is the reason Bobcat Engines can create more torque than prior engines used in Bobcat equipment. Combustion pressure plays an important role as it affects engine torque, noise, fuel efficiency and long-term performance.
Bobcat Engines create more torque because they are specially designed to handle more combustion pressure than prior engine designs. Inside an engine, combustion is basically an explosion that creates pressure. The bigger the explosion, the greater the pressure. As a result, more torque is created. While the concept seems simple, an engine has to be specifically designed to accomplish this benefit.
It’s easy to look at specs and see how much power (torque) is generated by an engine. However, specs don’t demonstrate how often the engine can actually create that amount of torque.
Some engines used in compact equipment only produce maximum torque over a narrow sliver of the engine's total operating range. Due to the varying workloads of compact equipment, even the best operators struggle to keep the engine operating within that range and performance suffers.
Bobcat Engines produce high- performing torque across a much wider range, up to six times broader than other engines used in compact equipment. Operators of all skill levels can easily maintain the power available, increasing overall performance.
Non-DPF Tier 4 compliant Bobcat machines automatically vary the Bobcat Engine’s combustion pressure to produce the proper torque for the job. More engine combustion pressure is necessary to increase performance during torque-demanding jobs (such as digging, pushing and lifting), but not every job requires it. When less torque is required of the engine (such as light duty operation or driving the machine across a worksite), the machine detects it and reduces engine combustion pressure, resulting in lower engine noise and better fuel efficiency.
Over time, an engine’s internal components wear and it becomes less efficient. As a result, it loses power (torque). Since non-DPF Tier 4 compliant Bobcat machines can manipulate engine combustion pressure, they can also compensate for engine wear by increasing the combustion pressure as the engine ages. This provides consistent engine power (torque) for the life of the engine.
For over a decade Bobcat loaders, compact excavators, and ToolcatTM utility work machines have been equipped with standard machine shutdown protection that monitors engine and hydraulic functions. The Bobcat Engine continues to improve these investment-saving features.
Prior to the Bobcat Engine, engine coolant and hydraulic oil temperatures were monitored. If these functions fell outside of their normal operating ranges, the system alerted the operator and shut down the machine to prevent catastrophic damage.
With the Bobcat Engines, machine shutdown is still possible. However, instead of shutdown being the only solution, the system monitors and manages coolant and oil temperatures to prevent them from reaching a point where the machine must be shut down. This prevents engine damage, minimizes engine wear and keeps operators working.
Extreme cold weather can be dangerous for diesel engines. If a machine begins working hard before the engine reaches its proper operating temperature, the engine and hydraulic oils cannot properly lubricate critical components. This causes premature wear and even total failure of the components, leading to downtime and high repair costs.
Bobcat Engines are automatically protected from these risks. Anytime the engine oil temperature is below its normal operating range, the machine temporarily increases engine idle speed (rpm) to help the engine oil reach its operating temperature faster. If the normal idle speed of the engine is 1100 rpm, for example, it will temporarily increase to 1300 rpm. This is similar to how automotive engines are designed for cold weather performance.
The machine also temporarily limits the maximum engine speed (rpm) to prevent premature component wear or failure. For example, if the normal maximum engine speed is 2800 rpm, it will temporarily decrease to 1600 rpm until the engine oil is warm.
Depending on the engine oil temperature, the protection may activate for several seconds to a few minutes. The word “cold” displays on the instrument panel until the protection system deactivates.
Bobcat loaders are known for fast and easy serviceability, and the new Bobcat Engine continues this advantage. The exclusive transversely-mounted engine puts daily maintenance within easy reach. Preventative maintenance becomes simple, reducing your operating costs and adding to your bottom line: